It's only a few thou but the motor place will do it to the correct fitment anyway. Oil holes need drilling through the piston to provide adequate lubrication to the pin - just copy how the Zetec pistons look. I'm assuming LET pistons are very similar to XE here, as that is what I'd have had to do for my ZVH. I went for Eagle rods and Arias in the end as they were a good price.